Adding command to a Tkinter OptionMenu?

问题:

I'm writing some code in Python 2.7.8 which includes the OptionMenu widget. I would like to create an OptionMenu that calls a function when the option is changed but I also want the possible options to be found in a list, as my final OptionMenu will have many options.

I have used the following code to create an OptionMenu that calls a function:

from Tkinter import*

def func(value):
    print(value)

root = Tk()

var = StringVar()
DropDownMenu=OptionMenu(root, var, "1", "2", "3", command=func)
DropDownMenu.place(x=10, y=10)

root.mainloop()

I have also found the following code that creates an OptionMenu with options found in a list:

from Tkinter import*

root = Tk()

Options=["1", "2", "3"]
var = StringVar()
DropDownMenu=apply(OptionMenu, (root, var) + tuple(Options))
DropDownMenu.place(x=10, y=10)

root.mainloop()

How would I create an OptionMenu that calls a function when the option is changed and gets the possible options from a list?

回答1:

There is never a need for a direct apply call, which is why is is dreprecated in 2.7 and gone in 3.0. Instead use the *seq syntax. Just combine the two things you did. The following seems to do what you want.

from tkinter import *

def func(value):
    print(value)

root = Tk()
options = ["1", "2", "3"]
var = StringVar()
drop = OptionMenu(root, var, *options, command=func)
drop.place(x=10, y=10)